From 5d6e3441feb2ad8c8ef1ab0068cc02b7d7ae1473 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?kleines=20Filmr=C3=B6llchen?= <filmroellchen@serenityos.org>
Date: Tue, 15 Feb 2022 00:32:55 +0100
Subject: [PATCH] AK: Fix FixedPoint to integral comparisons

Add tests to ensure that the fixed point numbers compare correctly to
integrals
---
 AK/FixedPoint.h             | 28 ++++------------------------
 Tests/AK/TestFixedPoint.cpp | 25 +++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 24 deletions(-)

diff --git a/AK/FixedPoint.h b/AK/FixedPoint.h
index 8a23f8d067..7f87935eb8 100644
--- a/AK/FixedPoint.h
+++ b/AK/FixedPoint.h
@@ -261,42 +261,22 @@ public:
     template<Integral I>
     bool operator>(I other) const
     {
-        if (m_value > 0)
-            return (m_value >> precision) > other || (m_value >> precision == other && (m_value & radix_mask));
-        if (other > 0)
-            return false;
-
-        return (m_value >> precision) > other || !(m_value >> precision == other && (m_value & radix_mask));
+        return !(*this <= other);
     }
     template<Integral I>
     bool operator>=(I other) const
     {
-        if (m_value > 0)
-            return (m_value >> precision) >= other || (m_value >> precision == other && (m_value & radix_mask));
-        if (other > 0)
-            return false;
-
-        return (m_value >> precision) >= other || !(m_value >> precision == other && (m_value & radix_mask));
+        return !(*this < other);
     }
     template<Integral I>
     bool operator<(I other) const
     {
-        if (m_value > 0)
-            return (m_value >> precision) < other || !(m_value >> precision == other && (m_value & radix_mask));
-        if (other > 0)
-            return true;
-
-        return (m_value >> precision) < other || (m_value >> precision == other && (m_value & radix_mask));
+        return (m_value >> precision) < other || m_value < (other << precision);
     }
     template<Integral I>
     bool operator<=(I other) const
     {
-        if (m_value > 0)
-            return (m_value >> precision) <= other || !(m_value >> precision == other && (m_value & radix_mask));
-        if (other > 0)
-            return true;
-
-        return (m_value >> precision) <= other || (m_value >> precision == other && (m_value & radix_mask));
+        return *this < other || *this == other;
     }
 
     // Casting from a float should be faster than casting to a float
diff --git a/Tests/AK/TestFixedPoint.cpp b/Tests/AK/TestFixedPoint.cpp
index 8127837ab0..5192f07f94 100644
--- a/Tests/AK/TestFixedPoint.cpp
+++ b/Tests/AK/TestFixedPoint.cpp
@@ -73,6 +73,31 @@ TEST_CASE(rounding)
     EXPECT_EQ(Type(-1.5).ltrunk(), -1);
 }
 
+TEST_CASE(comparison)
+{
+    EXPECT(Type(0) < 1);
+    EXPECT(Type(0) <= 1);
+    EXPECT(Type(0) <= 0);
+    EXPECT(Type(-10) <= -10);
+
+    EXPECT(Type(4.25) > 4);
+    EXPECT(Type(4.25) >= 4);
+    EXPECT(Type(4.25) <= 5);
+    EXPECT(Type(4.25) < 5);
+    EXPECT(Type(1.5) > 1);
+
+    EXPECT(!(FixedPoint<4, u8>(2) > 128));
+    EXPECT(!(FixedPoint<4, u8>(2) >= 128));
+
+    EXPECT(Type(-6.25) < -6);
+    EXPECT(Type(-6.25) <= -6);
+    EXPECT(Type(-6.75) > -7);
+    EXPECT(Type(-6.75) >= -7);
+
+    EXPECT(Type(17) == 17);
+    EXPECT(Type(-8) != -9);
+}
+
 TEST_CASE(cast)
 {
     FixedPoint<16, u32> downcast_value1(FixedPoint<32, u64>(123.4567));